This disclosure relates generally to methods and apparatus for expanding tubular members in a wellbore, such as casing, liners, sand screens, or other expandable tubular members. More particularly, this disclosure relates to apparatus and methods that utilize downhole expandable tubular members coupled with a sealed releasable connection.
A branch of solid expandable technology involves apparatus for expanding tubular members that utilize hydraulic forces. As usual, these apparatus rely on an expansion cone to radially expand and plastically deform the tubular members, but in particular, these apparatus rely on pressure across a cup to displace the expansion cone along the tubular members. To expand the tubular members from down-hole to up-hole ends, the cup is typically located up-hole from the expansion cone. The cup seals against the tubular member that is expanded. A problem occurs when the cup exits the tubular member. The pressure across the cup is lost before an up-hole section of the tubular member located between the expansion cone, and the cup is expanded.
One possible solution may be to use a mechanical force on the expansion cone to finish expanding the tubular member, for example by pulling with rig equipment on the expansion cone via a work string. To be successful, this solution necessitates that the rig equipment has a pulling capacity that exceeds the force that resists displacement of the expansion cone relative to the expandable tubular member, and that the expandable tubular member is sufficiently well anchored in the wellbore so that it does not move with the expansion cone. Cases where this solution is unsuccessful, are sometimes encountered.
Thus, there is a continuing need in the art for methods and apparatus for expanding tubular members in a wellbore.